Ours is a ancestral house in Chennai (brought by my grandfather and one additional room was built by my father later) in which we lived from 1976 and I am the only son and three younger sisters are also there. We are all married and living in different places. Only my parents are living in that house. Now my father is planning to sell that house due to its old condition. My queries are given below:

1)Has the three daughters have any legal right in the proceeds of the sale and on what basis and how much share as per law.2)what options available to my parents after selling the house.3)Do my father need to make a will now.